It was at once so dark that the two captives could not see each other, though only the width of the table separated them. Everything was profoundly still; not a sound came from the men in the other rooms. Presently Thorndyke whispered, “Look, do you see that red light overhead?”
“Yes,” said Johnston, “it looks like a star.”
“It is our bonfire,” said Thorndyke, “that's what betrayed us.”
Again the vessel began to sink, and more rapidly than ever; indeed, as Thorndyke expressed it, he had the cool feeling that nervous people experience in going down quickly in an elevator.
“If we go any lower,” he added, as the great rubber hull seemed to struggle like some living monster, “the sides of this thing will collapse like an egg-shell and we will be as flat as pancakes.”
“You need not fear, we have much lower to go!” It was the captain's voice, but they could not tell from whence it came. Then they heard again the seductive music, and it was so soothing that they soon fell asleep.
They had no idea how long they had slept, but they were awakened by the ringing of a bell and felt the vessel was coming to a stop. They were still far beneath the surface; indeed, the boat was resting on the bottom, for in the light of two or three powerful search-lights they saw a wide succession of submerged hills, vales, and rugged cliffs. Before them was a great mountain-side and in it they saw the mouth of a dark tunnel. They had scarcely noticed it before the vessel rose a little and glided toward the tunnel and entered it. Through the glass walls they could see that it was narrow, and that the ragged sides and roof were barely far enough apart to admit them.
Suddenly one of the men came in and drew a curtain down behind them, and, with a vexed look on his face retired.
When he was gone Johnston put his lips close to Thorndyke's ear and whispered:
“Did you see that?”